1. Field of the Invention
The present invention relates generally to the field of bookbinding, and more particularly, to a bookbinding structure and method that may be used with a wrap-around book cover.
2. Description of Related Art
Bookbinding systems utilizing binder strips are well known. Binder strips are used to bind pages together to form a book in which the binder strip forms the spine of the book. Binder strips which use a heat activated adhesives of low and high viscosity are used to bind a stack of sheets using heat and pressure which are applied to the strip and stack using a special purpose binding machine.
U.S. Pat. No. 4,496,617, the contents of which are hereby fully incorporated herein by reference, describes such a binding strip. The strips include an elongated paper substrate and an adhesive matrix disposed on the substrate. The matrix includes a central adhesive band which is heat activated and which has a relatively low viscosity when activated and a pair of outer adhesive bands. The outer bands are also heat activated, but are of a relatively high viscosity. The central adhesive band functions to secure the edges of the pages to be bound together and to the substrate and the outer bands function to secure the front and back cover pages to the substrate.
Such prior art binder strips are, however, not suitable for some applications due to the appearance of books bound by such strips. The spines of books bound by the conventional binder strips are often devoid of any printed information because the binder strips require specialized equipment for printing on the strip. Moreover, it is sometimes desirable to have a uniform cover having a continuous design from the front cover to the back cover, frequently including the spine. A conventional binder strip cannot provide a bound book having a cover with such a continuous design.
Another prior art bookbinding system, such as disclosed in U.S. Pat. No. 4,289,330, utilizes a continuous cover structure that forms the front and rear covers of the bound book together with the spine. A heat activated adhesive is deposited on the inside of the cover structure to secure the individual pages together. A significant disadvantage of such continuous cover structures is that many printing processes utilize heat sensitive inks which would be adversely affected by the heat applied to the cover structure during binding. Thus, it would not be possible to print on the cover structure using such popular printing processes. Furthermore, the presence of the adhesive on the cover structure can be bulky thereby making printing difficult using some types of printers. In addition, somewhat specialized equipment is needed to carry out the binding process.
The present invention overcomes the shortcomings of the above-described prior art. It is possible to carry out the binding process using the same machine used to bind books using conventional binder strips of the type disclosed in U.S. Pat. No. 4,496,617. Some of the embodiments of the invention permit the front and rear covers and the spine of the final bound book to be printed prior to binding using a wide variety of printing techniques including techniques employing heat sensitive inks. These and other advantages of the present invention will become apparent to those skilled in the art upon a reading of the following Detailed Description of the Invention.